They are amphibians. That means they spend part of their life as a water animal and part as a land animal.
Their skin is very sensitive. They die in polluted water.
Frogs are carnivores. That means they eat other animals. They have teeth inside their huge mouths, but the teeth aren't used for chewing, just for holding because frogs swallow their food whole.
Frogs use their eyes to help them swallow. They pull their eyeballs into the mouth to push food down into their tummies.
Their bulging eyes also help them see in almost any direction.
Their strong back legs are good for jumping and for swimming.
They have to come to the surface to breathe, otherwise they drown.
Male frogs are smaller than female frogs but they are a lot noisier. Different sorts of frogs make different calls.
This is a spotted tree frog.
This is a green tree frog.
Most frogs mate in water.
As the female releases her eggs the male releases his sperm to fertilise the eggs.
The eggs are protected by a jellylike substance. This mass of eggs and jelly is called frog spawn.
After mating the parents have nothing more to do with each other or their future babies
If the eggs don't get eaten by birds, fish or insects or the water doesn't become polluted or dry up, tiny tadpoles will hatch from the eggs. Tadpoles have long tails.
Tadpoles eat only plants so they are called herbivores.
As they eat they get bigger and bigger.
Like fish they have gills so tadpoles can only breathe underwater.
Tadpoles get their back legs first.
Then their gills disappear and lungs develop inside the body.
Their front legs develop where the gills were.
The little frog now has to have its head out of water to breathe.
The tail gradually disappears.
It's now a tiny adult frog.
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